Fiber optic networks

1
Acquisition of spectroscopic and computational
instruments for undergraduate education and
research in nonlinear optical materials
James Butler, Pacific University, DMR 0521496
Applications
Optical Limiters
Optical limiters are devices that can be used to
control the brightness of the light that reaches
a sensitive optical component

• Fiber optic networks
• must be fast-acting
• must integrate into fiber systems
• must operate at infrared wavelengths
• Eye protection
• scope sights
• binoculars
• must operate at both visible and infrared
  wavelengths

Bright Light In Dim Light Out
The optical limiters in this investigation use
nonlinear absorbers. The percentage of light
that these materials absorb increases with the
intensity of the incident light.
2
Optical Limiting in Capillary Waveguides at
Infrared Wavelengths
James Butler, Pacific University, DMR 0521496
3
Molecular Modeling Results
James Butler, Pacific University, DMR 0521496
Undergraduate student, Joshua D. King, completed
his senior thesis in chemistry titled,
Investigation of the electronic Spectroscopic
Properties of Phthalocyanines and Related Dye
Molecules Using Time-Dependent Density Functional
Theory.

• SOFTWARE IMPLEMENTATION
• Developed modeling protocol using the TD-DFT
  implementation in the ADF software package
• The ADF implementation of TD-DFT with Slater type
  orbitals was found to be superior in predicting
  electronic spectra of both ground and excited
  states.
• The software also runs Parallel on our Power
  Macintosh, greatly improving computation times.
• Software License supported by internal Faculty
  Development Grant from Pacific University to
  co-Pi Johnson

• SCIENTIFIC PROGRESS
• Results to Date
• A computational study of the effect of macrocycle
  size and symmetry was undertaken for a series of
  Magnesium Phthalo- and Naphthalo-cyanines
• Simulated electronic absorption spectra for
  ground singlet, S0, first excited singlet, S1,
  and first excited Triplet states were calculated
  and are shown to the right.
• Ground state MO density is observed to be a ?
  orbital with electron density distributed equally
  on the thalocyanine plane. Excited singlet states
  are observed to concentrate MO density on a
  single axis of the molecule.
• When the two molecular axes are of the same
  length, the LUMO orbitals are degenerate.
  However, counter to expectations, for molecules
  with unequal length in the axes of the macrocycle
  plane, the lower energy virtual orbital
  concentrates MO density on the short axis. This
  is the origin of splitting in the ground state
  spectra.